package com.TestDemo.Test1;

import org.junit.Test;

import java.util.HashSet;
import java.util.UUID;

public class TestUUID {

    @Test
    public void testUUID(){

        HashSet<Object> hashSet = new HashSet<>();
        for (int i = 0; i < 10000*1000; i++) {
            String ss = UUID.randomUUID().toString();
            hashSet.add(ss);
        }

        System.out.println("有："+hashSet.size());

    }
}
